Apparatus for wet drilling

ABSTRACT

A wet drilling arrangement in which an auger-like drill stem has a drill bit secured to one end and a drive motor secured to the other end for rotating the drill stem and bit. The bit has a fluid passage therethrough and the drill stem is hollow and the shaft of the drive motor is also hollow and a rotary fluid connector is mounted on the shaft of the drive motor at the end thereof opposite the drill stem whereby fluid, such as water, can be supplied to the region being drilled by the bit while the fluid connection is free of working loads.

United States Patent 1191 Leibee et al. Oct. 9, 1973 [54] APPARATUS FOR W DRILLING 2,848,196 8/1958 Simmonds 175/122 X 2,963,274 12/1960 Failing 175/207 x [75] Inventors: Donald L. Lelbee, Belfry, Ky.; 2 99 0 4 8/1961 175 X Seibert k Everett, 3,053,330 9 1962 Arthur 175 170 x [73] Assignee: Kennametal Inc., Latrobe, Pa.

Primary ExaminerDavid H. Brown [22] plied May 1972 AttorneyMelvin A. Crosby [21] Appl. No.: 250,643

[52] US. Cl. 175/170, 175/207 [51] Int. Cl E21b 3/02 [58] Field of Search 175/122, 170, 203, 175/207, 216, 320

[56] References Cited UNITED STATES PATENTS 2,547,609 4/1951 Vanderzee 175/207 X 2,797,066 6/1957 Sewell 175/122 2,960,311 11/1960 Scott.... 175/170 X 3,054,465 9/1962 Fish 175/207 X 1,395,706 11/1921 Greve 175/170 X 2,016,785 10/1935 Lawlor 175/170 5 7 ABSTRACT A wet drilling arrangement in which an auger-like drill stem has a drill bit secured to one end and a drive motor secured to the other end for rotating the drill stem and bit. The bit has a fluid passage therethrough and the drill stem is hollow and the shaft of the drive motor is also hollow and a rotary fluid connector is mounted on the shaft of the drive motor at the end thereof opposite the drill stem whereby fluid, such as water, can be supplied to the region being drilled by the bit while the fluid connection is free of working loads.

5 Claims, 1 Drawing Figure APPARATUS FOR WET DRILLING The present invention relates to a wet drilling arrangement, particularly for drilling in earth formations as in connection with mining operations.

Drilling in earth formations is widely practiced during mining and much of the drilling takes place underground. The drilling often consists of the drilling of fairly small holes in a formation for various reasons and, when this work is done underground, a great deal of fines and dust can be developed which creates hazardous and unhealthy conditions.

It is desirable in such cases to carry out drilling operations with a supply of liquid, such as water, to the drilling tool thereby greatly to reduce or to eliminate the hazardous conditions referred to.

Wet drilling systems in which a fluid, such as water, is supplied to the drill bit are known, but, heretofore, such systems have operated by introducing a fluid connector between the drive motor and the hollow drill string for supplying fluid to the drill string. Such an arrangement, while satisfactory for supplying fluid to the drill bit, disposes the rotary fluid connector in a position where it is subjected to the axial drilling thrusts, and it is not uncommon for the drilling string or the rotary fluid connector ,to fail, I 1

With theforegoing in mind, a primary object of the present inveniion is the provision of a wetdrilllng system in which the rotary fluid connector is protected from drilling thrusts and wherein the drill string is not in any way weakened by providing apertures therein for receiving the fluid.

Still another object is the provision of a wet dril'ing system of the nature referred to which is more inexpensive than previous wet drilling systems and which is substantially free of operational and maintenance problems.

These and other objects and advantages of the present invention will become more apparent upon reference to the following detailed specification taken in connection with the accompanying drawing.

BRIEF SUMMARY OF THE INVENTION According to the present invention, a drilling system is provided in which a drive motor has a hollow shaft extending completely therethrough. The hollow shaft at one end is adapted for connection to a drive socket which, in turn, is adaptedfor receiving the drive shank at one end ofa tubular drill string which may be in the form of an auger.

At the free end of the drill string, there is a bit for cutting formations and which has a fluid passage therethrough communicating with the interior of the tubular drill string. Mounted on the tubular motor shaft at the side of the motor opposite the drive socket is a rotary fluid connector through which fluid is supplied to the tubular motor shaft to flow therethrough, and then through the drive socket and into the tubular drill stem and from the tubular drill stem through the bit to the region being drilled.

The described arrangement permits the strongest possible construction of the drive socket and shank and tubular drill stern and disposes the rotary fluid connector at a point where it is not subjected to axial stress or possible damage from being pushed against a formation being drilled.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings somewhat more in detail, the drilling arrangement shown comprises a bit 10, which is illustrated in an exemplary manner and which has a flow passage 12 extending 'therethrough and communicating with the interior of a tubular drill string element 14 which may have a spiral rib 16 applied thereto so that the material taken by the bit is withdrawn from the hole being formed.

Drill string 14 is extensible as by threaded connector 18 interposed between adjacent sections of the drill stem and with connector 18 having an axial passage 20 extending therethrough.

At the end of the drill string opposite bit 10, the drill string is welded to a tubular drive shank 22 which threads into a tubular drive socket 24. Drive socket 24 is rotatably supported on bearings 26 which are sealed in a housing 28. Drive socket 26 is connected by a key 30 to a tubular motor shaft 32 which extends completely through a motor 34 that may be flange mounted to one end of housing 28. Motor 34 may, for example, be a fluid operated motor and be provided with conduit means 36 for the supply of actuating fluid to' the motor.

According to the present invention, tubular shaft 32 extends completely through the housing of the motor and on the side of the motoropposite drive socket 24 has a rotary fluid connector 38 mountedthereon to,

which is connected. a'supply conduit-4Q for drilling fluid. The drilling fluid supplied via conduit 40enters tubular shaft 32 andflows axially therethrough and through drive shank 22 and the tubtila'r d'rill string to the bit 10 and through the passage 12 in bit 10 to the region being drilled. Inasmuch as the fluid may be supplied under relatively high pressure, it is advantageous to seal against leakage and this is accomplished by providing a seal element 42 in the motor adjacent the point where shaft 32 emerges on the side facing drive socket 24. The shaft 32 is then extended to the point that it telescopically fits inside drive shank 22 with a resilient rubberlike seal 44 being provided in a recess 46 formed in drive socket 24. i

Recess 46 confines the seal element, or bushing, 44 on the radially outer side and on the end facing away from drive shank 22 while, on the side of bushing 44 facing drive shank 22, drive socket 24 has a bore 48 for receiving a tenon portion 50 formed on the end of the drive shank. The described arrangement is such that, when the drive shank 22 is threaded into position in drive socket 24, the end of tenon portion 50 of the drive shank engages the adjacent end of bushing 44 and compresses the bushing into sealing engagement with the walls of recess 46 in the drive socket and with the adjacent outer surface of tubular motor shaft 32 and with the end of tenon 50 of drive shank 22.

The arrangement is, thus, fully sealed against the leakage of liquid and relatively high pressure liquid can be supplied via conduit 40 without any problems arising because of leakage of the liquid into bearings 26 or along shaft 32 into the motor.

In order to provide firm seating of the drive shank 22 and drive socket 24, washers may be provided at 52 to provide for some axial adjustment of drive shank 22 and drive socket 24 thereby to produce the desired degree of compression of resilient bushing 44.

It will be appreciated that the fluid connector 38 is free of any axial drilling thrusts or of any bending moments that might be imposed on the drill string and that there is no possibility of the fluid connector being jammed into a formation during a drilling operation. The drill string and drive shank and drive socket can be formed to realize the maximum strength and the maximum drilling thrusts can be imposed on the drill string without damaging the rotary fluid connectors At the same time, maintenance'of the arrangement is quite simple and the rotary fluid connector can easily be replaced or serviced at any time without dismantling the motor from the drill string.

What is claimed is:

1. In an apparatus for wet drilling, especially in earth formations; auger means having a drill bit at one end and a drive shank at the other end, a drive motor having a drive shaft, a tubular drive member telescopically and nonrotatably engaging one end of said shaft and having a socket therein for telescopic engagement with said drive shank, a fluid connector rotatable on the other end of said shaft, fluid passage means leading from said connector through said shaft and drive member and drive shank and auger means to said drill bit and through said drill bit to' the working region of the drill bit, a resilient bushiggin said drive memberclosely surrounding said sha t. said drive shank having an' end region engageable with one end of said resilient bushing, means responsive to movement of said shank into said drive member for compressing said bushing into sealing engagement with said shaft and drive member, and means for retaining said shank in telescopic engagement with said drive member and also in engagement with said bushing.

2. An apparatus according to claim 1 which includes a housing fixed to said motor on the auger side thereof. and thrust bearing means in eaid housing operatively associated with said drive member and bearing axial thrusts imposed thereon during working of said apparatus.

3. An apparatus according to claim 1 in which said auger means is made up of sections in end to end relation, and a tubular coupling member interposed between and interconnecting adjacent ones of said sections at the opposed ends thereof.

4. An apparatus according to claim 1 in whch said end region of said shank which engages said bushing comprises a tubular tenon formed on the end of said shank opposite the auger end thereof, said drive member having an annular recess in which said bushing is mounted which is a close fit on said shaft on the side facing said motor and which is a close fit on said tenon on the side facing said shank the end of said tenon also sealing against said bushing when said tenon engages said bushing.

5. An apparatus according to claim 1 in which said socket and said shank have complementary threads formed thereon for retaining the shank in engagement with the drive'member; 

1. In an apparatus for wet drilling, especially in earth formations; auger means having a drill bit at one end and a drive shank at the other end, a drive motor having a drive shaft, a tubular drive member telescopically and nonrotatably engaging one end of said shaft and having a socket therein for telescopic engagement with said drive shank, a fluid connector rotatable on the other end of said shaft, fluid passage means leading from said connector through said shaft and drive member and drive shank and auger means to said drill bit and through said drill bit to the working region of the drill bit, a resilient bushing in said drive member closely surrounding said shaft, said drive shank having an end region engageable with one end of said resilient bushing, means responsive to movement of said shank into said drive member for compressing said bushing into sealing engagement with said shaft and drive member, and means for retaining said shank in telescopic engagement with said drive member and also in engagement with said bushing.
 2. An apparatus according to claim 1 which includes a housing fixed to said motor on the auger side thereof, and thrust bearing means in said housing operatively associated with said drive member and bearing axial thrusts imposed thereon during working of said apparatus.
 3. An apparatus according to claim 1 in which said auger means is made up of sections in end to end relation, and a tubular coupling member interposed between and interconnecting adjacent ones of said sections at the opposed ends thereof.
 4. An apparatus according to claim 1 in which said end region of said shank which engages said bushing comprises a tubular tenon formed on the end of said shank opposite the auger end thereof, said drive member having an annular recess in which said bushing is mounted which is a close fit on said shaft on the side facing said motor and which is a close fit on said tenon on the side facing said shank the end of said tenon also sealing against said bushing when said tenon engages said bushing.
 5. An apparatus according to claim 1 in which said socket and said shank have complementary threads formed thereon for retaining the shank in engagement with the drive member. 